Technical Field
The present invention relates to an optical fiber and a manufacturing method thereof, particularly to an optical fiber in which a beam control property of light emitting from an emitting end and a manufacturing method thereof.
Related Art
The optical fiber is a light guide member, in which the light incident at an incident end from a light source propagates and emits outward from the emitting end. The optical fiber includes a core that is of a core wire, a clad that covers an outside of the core, and a coating material that covers the outside of the clad. The optical fiber is configured such that the light propagates in the core by reflecting the light at an interface between the core and the clad using a difference in refractive index between the core and the clad.
Usually, an additional external optical system typified by various lenses is frequently connected to the emitting end of the optical fiber. Therefore, the external optical system performs beam control of the light emitting from the emitting end of the optical fiber.
There is also a proposal in which various lenses are directly formed by performing laser processing to the emitting end of the optical fiber or near the emitting end, thereby performing the beam control of the light emitting from the optical fiber.
For example, in the configuration of the optical fiber disclosed in Japanese Unexamined Patent Application Publication No. 2006-510057 (Translation of PCT Application) (Patent Document 1), surface removal processing is performed to form the lens by irradiating the emitting end with a laser beam, and the lens performs the beam control of the light emitting from the optical fiber. In the configuration of the optical fiber disclosed in Japanese Unexamined Patent Publication No. 2005-292382 (Patent Document 2), a refractive index change is induced to form the lens by irradiating the vicinity of the emitting end, and the lens performs the beam control of the light emitting from the optical fiber.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2006-510057 (Translation of PCT Application)
Patent Document 2: Japanese Unexamined Patent Publication No. 2005-292382